Rotary piston internal combustion engine, especially of trochoidal construction

ABSTRACT

A rotary piston internal combustion engine, especially of trochoidal construction which essentially consists of lateral parts and of at least one casing housing, in case of multi-disk internal combustion engines of one or several intermediate parts, with a gas-sealing element arranged between the end flanks of the lateral part, possibly of the intermediate part, and the casing housing; the end flanks of casing housing and/or of the lateral part, respectively, intermediate part, are provided with a recess, in which are accommodated metallic gas-sealing elements that consist of a material with high heat conductivity.

Lamm

[ 4] ROTARY PISTON INTERNAL COMBUSTION ENGINE, ESPECIALLY OE TROCHOIDAL CONSTRUCTION [75] Inventor: Heinz Lamm, Esslingen St.

Bernhardt, Germany [73] Assignee: Daimler-Benz Aktiengesellschaft,

Stuttgart-Untertuerkheim, Germany [22] Filed: Apr. 114, 1971 [21] Appl. No.: 133,884

[30] Foreign Application Priority Data Apr. 14, 1970 Germany 2017769 [52] US. Cl. .f. 418/60, 418/149 [51] Int. CL... F01c 19/00, F04c 15/00, F04c 27/00 [58] Field of Search 418/60, 61, 149; 123/807;

[56] References Cited FOREIGN PATENTS OR APPLICATIONS 1,360,604 3/1964 France 418/149 [111 3,809,509 [451 May 7,1974

Primary Examiner-Carlton R. Croyle Assistant Examiner-John J. Vrablik Attorney, Agent, or Firm--Craig and Antonelli [5 7] ABSTRACT A rotary piston internal combustion engine, especially of trochoidal construction which essentially consists of lateral parts and of at least one casing housing, in case of multi-disk internal combustion engines of one or several intermediate parts, with a gas-sealing element arranged between the end flanks of the lateral part, possibly of the intermediate part, and the casing housing; the end flanks of easing housing and/or of the lateral part, respectively, intermediate part, are provided with a recess, in which are accommodated metallic gas-sealing elements that consist of a material with high heat conductivity.

20 Claims, 16 Drawing Figures PATENTEDHAY 19M 3.809.509

SHEET 1 UPS YATENTEDMAY 72914 I 3,809 509 sum 2 [IF 3 PATENTEU 7 I974 SHEET 3 0F 3 ROTARY PISTON INTERNAL COMBUSTION ENGINE, ESPECIALLY OF TROCHOIDAL CONSTRUCTION The present invention relates to a rotary piston internal combustion engine, especially of trochoidal type of construction, essentially consisting of lateral parts and at least of a casing housing, with multi-disk internal combustion engines, of one or several intermediate parts, with a gas-sealing element each arranged between the end flanks of the lateral part, possibly of the intermediate part, and of the casing housing.

The problem of the gas seal between the casing housing and the lateral part or intermediate part gains ever more in significance with increasing thermal loads of the drive unit ofa rotary piston internal combustion engine. Heretofore, the gas seal was solved satisfactorily on the basis of slight average pressure loads,.i.e., pme 2 l kp/cm by surfaces ground plane parallel of the parts clamped and connected together by tie rods. Additionally, gas-sealing elements arranged between the surfaces and constructed primarily as rubber rings of differing shapes have become known for the further assistance of the gas seal. Since these prior art types of construction of the gas seals have no heat conduction function, they are hardly able to cope with present-day requirements, for with increasing power output of highly loaded engines, the temperature in the trochoidal space increases correspondingly so that the danger exists that the flat ground surfaces warp during the operating condition and cause untight or leaky places as regards the gas. The aim of the present invention is to eliminate these occurring shortcomings in an advantageous manner,

According to the present invention, it is proposed that the end flanks of the casing housing and/or of the lateral part or of the intermediate part are provided with a recess and in that metallic gas-sealing elements are accommodated in this recess which consist of a meterial having a high thermal conductivity.

According to the present invention, the gas-sealing I elements may be constructed as regards their size in such a manner that a gap provided for the gas entry results between the casing housing and the lateral part or the intermediate part.

The gap, which is limited in its width by the gassealing element, and the heat-conducting gas-sealing element conduct the heat flow in the casing housing from the hot zone into the cold zone and reduce the temperature peaks within the same housing which occur excessively strong at some places. Additionally, the gas-sealing elements absorbing heat from the casing housing again give off the heat thereof to the lateral part or intermediate part so that a heat transfer is made possible by way of large surfaces.

The warping danger, occurring heretofore as a result of different high temperatures at the running surfaces of the casing housing, of the lateral part or of the intermediate part, along which slide the radial sealing bars, the sealing bolts, the lateral strips and the oil seals, is far-reachingly eliminated and consequently the leakage gas quantity and escaping oil are considerably reduced. Furthermore, with the decrease of the casing running surface temperature, also a safe lubrication between the sealing bar head portion and the casing running surface is achieved and therewith a better gas seal from chamber to chamber is assured.

In an advantageous construction of the present invention, the recess arranged at the end flank of the casing housing may be constructed wedge-shaped, rectangular in the direction toward the outlet, and the gassealing element provided at counter piece for the recess may be constructed trapezoidally-shaped.

As a further feature according to the present invention, the recesses provided for the accommodation of the trapezoidally-shaped gas-sealing element may be constructed rectangularly in the casing housing and wedge-shaped in the lateral part or in the intermediate part.

In an advantageous manner, the recesses arranged in the casing housing may be provided with an essentially rectangularly-shaped cross section and the gas sealing elements provided for these recesses may be constructed correspondingly rectangular, possibly square, or of elongated oval shape, or elastic gas-sealing elements may be provided which are shaped in cross section like letters, for example, like N, Z, V or U.

According to the present invention, the recess at the end flank of the casing housing may be constructed semi-oval and the gas seal element may be provided with a circular shape matched to the recess, though flattened in the direction toward the end flank.

In order to provide the gas seal element primarily for the heat conduction, it is proposed as preferred embodiment for achieving a very effective reduction of the peak temperatures that the gas-sealing element ar-- ranged between the casing housing and the lateral part or intermediate part is in operative connection with the cooling water. a

In order to-attain this, according to the present invention, the gas-sealing element may be provided with dividual pins.

According to the present invention, the gas-sealing element may also be provided with individual bars. A further feature of the present invention may be a gas-sealing element which is provided with a continuous bar that has at most the length ofthe gas-sealing element.

According to the present invention, the parts projecting from the gas-sealing element and constructed as pins or bars may be arranged on one side or on both sides at the gas-sealing element.

With this last mentioned construction, on the one hand, a still more favorable gas seal between the metallic surfaces of the casing housing and lateral part or intermediate part is achieved and, on the other, a considerably improved heat transfer is assured by reason of the parts of the gas-sealing element projecting into the cooling water. As a result of the strong decrease'of the temperatures, the arrangement of a gap becomes superfluous. In lieu thereof, if required, an additional rubber seal, for example, an O-ring, may be utilized for the gas and water seal.

Accordingly, it is an object of the present invention to provide a rotary piston internal combustion engine, especially of trochoidal construction which avoids the aforementioned shortcomings and drawbacks encountered in the prior art.

Another object of the present invention resides in a rotary piston internal combustion engine, especially of trochoidal construction, which assures an effective seal between the casing housing and the lateral or intermediate parts,

A further object of the present invention resides in a rotary piston internal combustion engine, especially of trochoidal construction, which is equipped with gas seals fully capable of satisfying to the requirements of the high power outputs of present-day engines.

A still further object of the present invention resides in a seal construction for rotary piston internal combustion engines which effectively decreases pressure peaks and therewith eliminates the danger of warping of the parts that might eventually cause gas leakages.

Still another object of the present invention resides in a rotary piston internal combustion engine which is characterized by a decreased danger of gas leakage as well as reduced oil loss.

A further object of the present invention resides in a rotary piston internal combustion engine of the type described above which assures an improved sealing effect from chamber to chamber. 1

These and further objects, features and advantages of the present invention will become obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, several embodiments in accordance with the present invention, and wherein:

FIG. 1 is a' partial cross-sectional view through a trapezoidally-shaped gas-sealing element in accordance with the present invention arranged in the casing housing;

FIG. 2 isa partial cross-sectional view through a trapezoidaIly-shaped gas-sealing element of the present invention arranged both in the casing housing as also in the lateral part;

FIGS. 3-6 are partial cross-sectional views through gas-sealing elements of the present invention arranged in the casing housing which are of different shapes;

FIGS. 7-9 are partial cross-sectional views of gassealing elements in accordance with the present invention arranged in the casing housing and shaped constructed like letters; and

FIGS. 10 and 11 are partial cross-sectional views through still further modified embodiments of gas I another modified embodiment of a gas-sealing element in accordance with the present invention arranged in the casing housing;

FIG. 14 is a partial cross-sectional view of a further embodiment of gas-sealing elements in accordance with the present invention provided with pin-like projections extending into the cooling space;

FIG. 15 is a partial cross-sectional view through a further modified embodiment with bar-like projections extending into the cooling space, taken substantially along the line XVXV of FIG. 14; and

FIG. 16 is a longitudinal cross-sectional view through a part of a rotary piston-internal combustion engine of three-disc construction provided with sealing elements in accordance with the present invention.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, and more particularly to FIGS. 12 and 16, FIG. 12 illustrates a plan view on the multi-disc rotary piston internal combustion engine, for example on the three-disc rotary piston internal combustion engine as shown in FIG. 16, taken in the direction of arrow X (FIG. 16) with the lateral housing part generally designated by reference character a removed. The threedisc rotary piston internal combustion engine of trochoidal construction includes three casings generally designated by reference characters 0, d and e, two lateral parts generally designated by reference characters a and b externally adjoining the housing casings c and e, respectively, and two intermediate housing parts generally designated by reference characters f and g. Gas-sealing elements generally designated by reference characters s are thereby arranged between adjacent housing parts (a, c; c, f;f, d; d, g; g, e; and e, b.) FIG. 12 illustrates the housing casing 0 provided with the internal running surface 6 and with the recess generally designated by reference character h for accommodating the gas sealing element. The polygonal piston p is rotatably supported in a conventional manner such that its piston corners always slide along the internal running surface 6 of a respective casing.

Various embodiments of gas seal elements and their arrangements .in the respective casing housings c and lateral parts a, b or intermediate parts f, g will now be described more fully hereinafter by reference to FIGS. 1-11 and 1315. In the embodiment of FIG. I, a gassealin'g element 3 arranged between a casing hosuing l and a lateral part 2 of a conventional rotary piston internal combustion engine, as illustrated in FIGS. 12 and 16 is accommodated according to this figure in a recess 4 of the casing housing 1 and is constructed trapezoidally-shaped as seen in cross section. The recess 4 arranged at an end flank 5 of the casing housing 1 and extending close to a casing contact or running surface 6 over the entire circumference, which has a larger filling volume than the gas-sealing element 3, is constructed wedge-shaped in the axial direction but is constructed rectangulatly in the direction toward the adjacent lateral part 2. The casing housing 1 and the lateral part 2 which are clamped together by means of tie rods or the like, press the gas-sealing element 3 initially into the wedge-shaped recess 4, whereby with a stronger pressing-in action the deformable gas-sealing element 3 partially fills out several free fields 7, 8, and 9 existing in the recess 4. The end flanks 5 and 5' of the casing housing 1 and of the lateral part 2 do not abut against one another between the gas-sealing element and the casing running surface 6, but instead form a gap 10 provided for the gas inlet or entry. An optimum in gas tightness and heat transfer is achieved by this measure whereby, by reason of the heat transfer, more uniform temperatures prevail at the circumference of the trochoid and from housing to housing. This is also true for the embodiments of the gas seal to be described more fully hereinafter.

According to FIG. 2, the gas-sealing element 11, also constructed trapezoidally-shaped, is accommodated not only in a recess 12 of the casing housing 1, but also in a recess 13 of the lateral part 2, whereby these recesses 12 and 13 differ from the recess 4 illustrated inFIG. I in that the wedge-shaped recess missing in the casing housing is arranged in an end flank 14 of the lateral part 2.

The recesses 8' in the casing housing 1 arranged according to FIGS. 3 and 4 have each a rectangular crosssection and the gas sealing elements 4a and 4b provided for these recesses are constructed either of elongated oval shape (FIG. 3) or of corresponding rectangular shape (FIG. 4) whereby the respective flanks l5 and 16 of the recesses 8' are not contacted by the gassealing elements in order to assure a deformation of the gas-sealing elements. A similar construction is illustrated in FIGS. 5 and 6. The gas-sealing elements 4c and 4d are constructed, on the one hand, square (FIG. 5), and on the other, circular( FIG. 6), whereby the circular sealing element 4d is flattened off at a sealing place 18 provided for the lateral part 2. In the embodiment of FIG. 5, the sealing element 4c is accommodated in a substantially squarerecess 8a which is adjoined outwardly thereof by a rectangular recess 8b to permit deformation of the sealing element 40. The sealing element 4d of FIG. 6 is accommodated in a square recess 8a. In view of the circular configuration of the sealing element 4 d, sufficient space remains in this embodiment for the deformation of the sealing element 4d, in case of need, even without the rectangular recess 8b of FIG. 5. Possibly all of the gas-sealing elements are constructed hollow, whose hollow spaces are filled with a gas or sodium.

Additionally, the gas-sealing elements generally designated by reference characters accommodated in the rectangular recess 8" of the casing housing 1 according to FIGS. 7, 8 and 9, which consist ofa springy or elastic material of any suitable conventional type and thus avoid a permanent deformation by reason of the compressive strain occurring as a result of the maximum expansion, are constructed in such a manner that they have in cross section the shape of a U, S, M or any other letter-like shape.

The gas-sealing and heat-conducting embodiments illustrated in FIGS. 10 and 11 are provided with openings 21 and 21' both in the housing casing 19 as also in the lateral part 20, which are specifically provided for the pin-like parts equal in number and individually projecting from a central portion 22 (FIGQIO) or 23 (FIG. I l) of the gas-sealing element 24. The parts constructed as pins 25 and 26' (FIG. 10) or as bars 27, 28 (FIG. II), are constructed of such length that the ends thereof protrude far into the cooling space of the casing housing 19 and of the lateral part and are circumcirculated by the cooling water. The trapezoidally shaped center section 22 of the gas-sealing element 24 according to FIG. 10 is accommodated in a wedgeshaped recess 20] of the lateral part 20 and in a rectangular recess 19 of the casing housing 19. I

According to FIG. 11, the center section 23 of the gas-sealing element 24 is constructed rectangularly. Only for the center section, a recess 19" also rectangularly arranged in the casing housing 19 is provided, whose dimensions are correspondingly larger than those of the center section 23in order to be able to partially fill out the free spaces 29 and 30 with sealing elements 31 and 32 constructed as O-rings, if so desired.

The arrangements made according to FIGS. 10 and 11 are not provided with a gap between the casing housing and the lateral part. The endv flanks ground flat are connected directly with each other.

FIG. 13 represents a cross-sectional view, on an en- 'larged scale, of still another modified embodiment in accordance with the present invention in which .the easing housing 1 is provided with recess 1' constructed approximately semi-oval, in which is arranged a sealing element 41 that is of circular shape matched to the aperture 1' except in the part thereof facing the end flank 10, where the sealing element is flattened off.

FIG. 14 illustrates a gas sealing element k, similar to FIG. 2 which is provided with pins 1 projecting into the cooling medium space of a housing part 2. If so desired, the sealing element k, in lieu of pin-like projections 1 provided only on one side, may also be provided with pin-like projections on both sides by the addition of the pin-like projections m, shown in dash and dot lines which then project into the cooling space of a respective casing housing.

FIG. 15 illustrates a gas sealing element n, taken along line XVXV of FIG. 14 which, in lieu of pins, is provided with bars 0 projecting into a cooling space from the gas sealing element n thereof.

All of the gas-sealing elements are preferably made from materials whose properties are composed of a good heat conduction (if possible a kcal/mhC) of a melting point preferably above 700C and of a modulus of elasticity of no more than about 12,000 kp/mm While I have shown and described several embodiments in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art, and I therefore do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifi cations as are encompassed by the scope of the appended claims.

I claim:

l. A rotary piston internal combustion engine which comprises housing means defining a chamber for a rotary piston including lateral housing parts and at least one casing housing, said lateral housing parts and casing housing having mutually facing end flanks, and gassealing means arranged between the end flanks of a respective lateral housing part and casing housing, characterized in that the end flanks of at least one of the two parts consisting of casing housing and lateral housing parts is provided with a recess means, in that metallic gas-sealing means are accommodated in said recess means which consist of a-material with high heat conductivity to-thereby reduce temperature peaks in the housing means occurring at certain places thereof by favoring the heat flow from a hot zone of the engine to a cold zone thereof, and in that the gas-sealing means are of larger size in relation to the recess means that a gap for the gas entry from said chamber results between the casing housing and a lateral housing part when said casing housing and lateral housing part are assembled together with the sealing means in the recess means.

2. A rotary piston internal combustion engine according to claim'l, characterized in that the recess means extend over the entire circumference of the engine.

3. A rotary piston internal combustion engine according to claim 1, characterized in that the engine is of trochoidal construction.

4. A rotary piston internal combustion engine ac cording to claim 1, characterized in that the recess means is arranged at the end flank of the casing housing and is constructed generally wedge-shaped but is of substantially rectangular shape at the end thereof facing the lateral part, and in that the gas-sealing means provided as counter element for the. recess means is constructed substantially trapezoidally shaped.

- in the lateral parts.

6. A rotary piston internal combustion engine accordingto claim 5, characterized in that the recess means isconstructed substantially semi-oval in crosssectional shape and in that the gas-sealing means has a circular shape matched to the recess with a flattened off portion facing the end flank.

7. A rotary piston internal combustion engine according to claim 5, characterized in that the recess means is of substantially square cross-section and in that the gas-sealing means is of approximately circular configuration and is in contact with the bottom and sides of the substantially square cross-section recess means.

8. A rotary piston internal combustion engine according to claim 1, characterized in that the engine is a multi-disk internal combustion engine and in that at least oneof the lateral parts forms an intermediate part between respective disks.

9. A rotary piston internal combustion engine according to claim 8, characterized in that several intermediate parts are provided.

10. A rotary piston internal combustion engine according to claim 5, characterized in that the'recess means are arranged in the casing housing and are of substantially rectangular cross section.

11. -A rotary piston internal combustion engine according to claim 10, characterized in that said gassealing means are substantially rectangular.

12. A rotary piston internal combustion engine according to claim 10, characterized in that said gassealing means are substantially square.

13. A rotary piston internal combustion engine according to claim 10, characterized in that said gassealing means are of elongated oval shape.

14. A rotary piston internal combustion engine according to claim 8, characterized in that said gassealing means are elastic and are letter-like in cross section.

15. A rotary piston internal combustion engine according to claim 1, characterized in that the recess means is formed by at least two mutually angularly spaced wall surfaces in said one part which extend into said one part away from the respective end flank thereof.

16. A rotary piston internal combustion engine according to claim 15, characterized in that said gassealing means is in heat-transfer contact with at least one of said wall surfaces at a place recessed in said one part and is additionally in heat-transfer contact with said other part over a substantial surface area.

17. A rotary piston internal combustion engine according to claim 16, characterized in that said other part is also provided with a recess means.

18. A rotary piston internal combustion engine according to claim 16, characterized in that said recess means is of wedge-shaped configuration in cross section formed by two converging surfaces, said gassealing means being of complementary shape to said wedge-shaped configuration and engaging with its side flanks in heat-transfer relationship at least over a substantial portion of said converging surfaces.

19. A rotary piston internal combustion engine according to claim 16, characterized in that said recess means in said other part is substantially rectangular in configuration and said metallic gas-sealing means is in contact with at least the bottom thereof.

20. A rotary piston internal combustion engine according to claim 1, characterized in that the gas-sealing means is of substantially oval configuration having two substantially rectilinear, parallel surfaces, one of said parallel surfaces being in contact with the bottom of said recess means and the other with the other of said 

1. A rotary piSton internal combustion engine which comprises housing means defining a chamber for a rotary piston including lateral housing parts and at least one casing housing, said lateral housing parts and casing housing having mutually facing end flanks, and gas-sealing means arranged between the end flanks of a respective lateral housing part and casing housing, characterized in that the end flanks of at least one of the two parts consisting of casing housing and lateral housing parts is provided with a recess means, in that metallic gas-sealing means are accommodated in said recess means which consist of a material with high heat conductivity to thereby reduce temperature peaks in the housing means occurring at certain places thereof by favoring the heat flow from a hot zone of the engine to a cold zone thereof, and in that the gas-sealing means are of larger size in relation to the recess means that a gap for the gas entry from said chamber results between the casing housing and a lateral housing part when said casing housing and lateral housing part are assembled together with the sealing means in the recess means.
 2. A rotary piston internal combustion engine according to claim 1, characterized in that the recess means extend over the entire circumference of the engine.
 3. A rotary piston internal combustion engine according to claim 1, characterized in that the engine is of trochoidal construction.
 4. A rotary piston internal combustion engine according to claim 1, characterized in that the recess means is arranged at the end flank of the casing housing and is constructed generally wedge-shaped but is of substantially rectangular shape at the end thereof facing the lateral part, and in that the gas-sealing means provided as counter element for the recess means is constructed substantially trapezoidally shaped.
 5. A rotary piston internal combustion engine according to claim 1, characterized in that the gas-sealing means is trapezoidally shaped, and in that the recess means provided for the accommodation of the trapezoidally-shaped gas-sealing means are constructed rectangularly in the casing housing and wedge-shaped in the lateral parts.
 6. A rotary piston internal combustion engine according to claim 5, characterized in that the recess means is constructed substantially semi-oval in cross-sectional shape and in that the gas-sealing means has a circular shape matched to the recess with a flattened off portion facing the end flank.
 7. A rotary piston internal combustion engine according to claim 5, characterized in that the recess means is of substantially square cross-section and in that the gas-sealing means is of approximately circular configuration and is in contact with the bottom and sides of the substantially square cross-section recess means.
 8. A rotary piston internal combustion engine according to claim 1, characterized in that the engine is a multi-disk internal combustion engine and in that at least one of the lateral parts forms an intermediate part between respective disks.
 9. A rotary piston internal combustion engine according to claim 8, characterized in that several intermediate parts are provided.
 10. A rotary piston internal combustion engine according to claim 5, characterized in that the recess means are arranged in the casing housing and are of substantially rectangular cross section.
 11. A rotary piston internal combustion engine according to claim 10, characterized in that said gas-sealing means are substantially rectangular.
 12. A rotary piston internal combustion engine according to claim 10, characterized in that said gas-sealing means are substantially square.
 13. A rotary piston internal combustion engine according to claim 10, characterized in that said gas-sealing means are of elongated oval shape.
 14. A rotary piston internal combustion engine according to claim 8, characterized in that said gas-sealing means are elastic and are letter-like in cross section.
 15. A rotary piston internal coMbustion engine according to claim 1, characterized in that the recess means is formed by at least two mutually angularly spaced wall surfaces in said one part which extend into said one part away from the respective end flank thereof.
 16. A rotary piston internal combustion engine according to claim 15, characterized in that said gas-sealing means is in heat-transfer contact with at least one of said wall surfaces at a place recessed in said one part and is additionally in heat-transfer contact with said other part over a substantial surface area.
 17. A rotary piston internal combustion engine according to claim 16, characterized in that said other part is also provided with a recess means.
 18. A rotary piston internal combustion engine according to claim 16, characterized in that said recess means is of wedge-shaped configuration in cross section formed by two converging surfaces, said gas-sealing means being of complementary shape to said wedge-shaped configuration and engaging with its side flanks in heat-transfer relationship at least over a substantial portion of said converging surfaces.
 19. A rotary piston internal combustion engine according to claim 16, characterized in that said recess means in said other part is substantially rectangular in configuration and said metallic gas-sealing means is in contact with at least the bottom thereof.
 20. A rotary piston internal combustion engine according to claim 1, characterized in that the gas-sealing means is of substantially oval configuration having two substantially rectilinear, parallel surfaces, one of said parallel surfaces being in contact with the bottom of said recess means and the other with the other of said two parts. 